Fuel generator



June 3, 1969 F. BEARD ETAL FUEL GENERATOR Filed Aug. 51,' 1967 Prev/400 flea/*0 W////a/77 6. 6/

INVENTORS mm a June 3, 1969 F. BEARD ETAL 3,447,511

FUEL GENERATOR Filed Aug. 31, 1967 Sheet 2 r 2 Frank/07 Bea/a W/ ///00? 6I Green INVENTORJ ATTORNEY United States Patent US. Cl. 1233 8 Claims ABSTRACT OF THE DISCLOSURE A method of generating fuel from raw crude oils, and the like, and the apparatus to accomplish this method comprising a fuel generator for the supply of fuel to an engine as a source of power, wherein the fuel is extracted from a supply of petroleum, utilizing the heat generated by the engine as a medium of extraction, and a novel means for starting the fuel generation.

Background of the invention In the production of petroleum, and the many connected activities, power is needed to activate pumps, and the like, and where gas is produced in plentiful quantities, this is used to provide the needed power. However, where low gravity petroleum is encountered, there is little gas, and pumping is necessary and fuel is required to operate the power engines. The refining of gas and higher grade fuels from comparatively low grade natural oils, is a well known art, but as known are for the most part large, fixed installations, not designed for production of small quantities as is required to operate an engine. This invention contemplates utilizing the heat generated by the engine to produce the fuel which will in turn operate the engine. Laboratory study of engines produces the following information as concerning a sixty-five horsepower gas engine:

Heat produced at full horsepower: B.t.u.s 65/HP/hr. 165,555 Exhaust heat rejection 90,000 Coolant heat rejection 125,000 Other heat-friction and accessory drives 349,445

Total 780,000

In other words, to recover sixty-five horsepower for one hour from the subject machine, will require a fuel of amount and quality necessary to produce 780,000 B.t.u.s in one hour, under the burning conditions characteristic of that engine.

The heat content of natural gas is ordinarlly adjusted to 1000 B.t.u.s per standard cubit foot, i.e., a cubic foot of gas at 60 F. at sea level pressure.

The heat energy available from certain crude oils, is about 18,000 B.t.u.s per pound of oil. Thus the above 780,000 B.t.u.s could be obtained from 43.4 lbs. of crude oil, per hour. Analysis of data obtained from laboratory study of certain crude oils, actually distilled in laboratory equipment, yields the following important facts:

Gravity, A.P.I. 60 F. 38.2-21.7 Boiling point F.. 110226 of volume recovered at F. 220450 10% of volume recovered at F 273482 40% of volume recovered at F. 500-520 Loss of gravity, A.P.I 7.8 Final gravity of residue, A.P.I 30.4

Since a recovery of engine fuel of five percent of the weight of oil treated for the 2l.7 gravity requires heating the oil from ambient, or 60 F., to 450 F., or a difference of 390 F., and recovery of 10% of the fuel 3,447,511 Patented June 3, 1969 requires raising the temperature to 482 F., or a difference of 422 F., there is relatively little additional heat required to get ten percent as to get five percent. However, to recover five percent of the oil, twenty times that much oil must be raised in temperature 390 F., while to recover ten percent requires that ten times as much oil must be raised 422 F. Thus:

5%=43.4 lbs. of oil, 20 43.4=868 lbs. oil/hr. 10%=43.4 lbs. of oil, 10 43.4=434 lbs. oil/hr.

resulting in requiring twice as much heat to get five percent of the oil as it does to get ten percent. The maximum horsepower, therefor, will require distilling heat energy of Since there will be heat losses in the transfer from the engine to the still, this number may be increased to 175,000 B.t.u.s. There is available from the exhaust 90,000 B.t.u.s and from the coolant 125,000 B.t.u.s, and it is obvious that the fuel generator must use the greater part of the heat from both the exhaust system and the coolant system. The coolant system of this engine operates with a pressurized radiator, at a temperature of 240 F. This means that approximately eighty percent of the heat is available as steam, at 12 p.s.i.

Still another parameter of interest in the design of this fuel generator is the fact that refining companies purchase crude oil from the producers at prices which are fixed by one hundred thirty years of experience, based on the properties of the crude oils, which are, in general, related to the specific gravity of the oils. The American Petroleum Institute has standardized this relationship by its own formula, which is expressed in API gravity. This term is used entirely throughout the free world for the purchase or sale of natural crude oils. A recent price sheet published for crude oil shows an average of $0.02 per degree of gravity, differential price increase with increase of gravity, or vice versa.

If the percentage of crude oil used for recovery of fuel is relatively low, the reduction of gravity of the average production from a pumping well would be low, and the cost of the fuel, if the average gravity of the oil was lowered less than 1 API, assuming the natural gravity to be slightly less than in increase point, then the remaining oil would be sold for the same price. Since the amount of oil used for pumping would be, at normal operating power, approximately twenty pounds per hour, which for twenty-four hours would be 480 lbs/day, or 1.58 barrels of oil at $2.65, or $4.17 per day. The comparable cost of Propane LPG at $0.15/ gal. is $9.34/day. It is, therefore, obvious that the hereindescribed apparatus represents an economically advantageous approach to the existing problem.

Summary of the invention The method of generating fuel for the operation of an engine from available petroleum employing mechanism comprising a species of refining equipment or still, designed to remove only a fraction of the lighter hydrocarbons from crude oil, either in the form of a dry gas, or sometimes as a distillate suitable for use in gasoline appliances, engines, automobiles, and other vehicles, or both; the said fractionating still to be operated by the heat rejected by the engine, a portion coming from the exhaust heat, and the remainder from the heat rejected by the cooling system, comprising the combination of means for:

(a) Preheating crude oil in a heat exchanger, utilizing waste engine coolant water heat.

- (b) Further heating the oil in. a second heat exchanger to a temperature sufficient to extract ten percent of the treated oil as gas.

(c) Maintaining a positive pressure on the fluid while it is being heated, to prevent escape of the gas, and maintaining a liquid vapor seal, controlled to permit the continuous influx of fresh oil at a rate which will permit taking ten percent of the oil, no more, and no less.

(d) Pumping the oil with a controlled volume pump to insure that the proper amount of oil is passed through the treating unit.

(e) Collecting the residue oil and pumping it back into the line to storage, whereby it is mixed by the turbulence of the pump and passage through the line.

(f) Passing the gas through the screens into a space where the volume is suflicient that the flow rate will diminish to a low value to permit the condensation and precipitation of the lower fractions thereof, as well as actual droplets of distillate, and

(g) Passing the gas into a second drying area, where the temperature is substantially below 500 F. to further condense such fractions as will drop out, thus leaving a gas stable enough to pass into a gas carburetor of the engine.

(h) Collecting the condensate in the second drying chamber and storing it for use in vehicles, and in starting the operation, as a gas-oil burner of the blow-torch type, as will be described.

All of the foregoing for the purpose of providing a gas equivalent to natural gas of the quality necessary for operating a gas engine; or for distillates of the quality satisfactory for gasolene or diesel engines, from the waste heat of the primary engine, without the waste of any of the fuel, and insofar as possible, without loss of price of the crude oil so treated and evaporated.

Brief description of the drawings FIGURE 1 is a perspective elevational view of the generator attached to a motor and operating a pump.

FIGURE 2 is an elevational view, partially in cross section, of the distillate tank and control.

FIGURE 3 is a fragmentary view of the heat exchange means employed.

FIGURE 4 is a fragmentary elevational view of the distillate storage control.

FIGURE 5 is an elevational view, partially in cross section, illustrating the temperature by-pass control.

Description 0 the preferred embodiment In the drawings, a pump having the usual counter balanced jack 45, operating on a bearing, pumps petroleum from the well 48, and has the usual polish rod 46 and production flow line 49 which leads into the separator 50 of a conventional type, or similar type of storage unit which will maintain an oil level at least three feet above the top of the dryer vessel hereinafter referred to. A conduit, as 51, leads from the separator to a tank or pipe line as 47 where a back pressure, or head, is encountered. A conduit 52 leads from the separator 50 into the heat exchanger 57 and directs a supply of petroleum through the preheating coils 58, and the conduit 53, containing preheated petroleum, leads from the heat exchanger .57 to the conduit 1 which is in flow connection with the distributor tube 32 and the tube 32 is provided with a series of slots 10, for the distribution of the oil against the walls of the inner distillation vessel 40 which is preferably cylindrical in form and is mounted in the .welded on the inside wall thereof at the opposite end to which the end plate 22 is detachably mounted as by bolts 23, 23 and a gasket 17 is mounted between the ring 16 and the end plate 22. The inner cylinder 40 is spaced from the inside Walls of the outer cylinder 92 by means of the flutes 93. An enclosure 18 is mounted at one end of the inner cylinder 40, preferably by welding same to the upper inside wall thereof and the bottom of said enclosure forming upwardly inclined baifies, provided with drain openings 94, 94.

A float valve consisting of the float 12, float arm 13, pivot 41 and closure 11 which seats against the Teflon seat 15 on the discharge conduit 3, extended through the end plates 39, 40 into the inner vessel 40, maintains a predetermined level of oil in the vessel 40.

A discharge conduit 19 is mounted in the inner vessel 40, andhas an open end upwardly inclined and parallel with the upper wall of the inner vessel, and in close proximity to said upper 'wall. This conduit extends through the end plates 40 and 29 and discharges into the second dryer 34 and comprises the flow line 7. The second dryer 34 is mounted on the top of the outer vessel 92, as by means of the supports 36, 36, welded to the outer surface of the vessel 92. A drain 9 is mounted in the conduit 19, extending through the bottom wall, to provide means for discharging condensate. A perforated bafiie 38 is mounted in the dryer 34 and a screen 39 is mounted on the said bafile 38. The bafile 38 and screen 39 are mounted at an angle to provide drainage by gravity of any mist remaining in the gas passing therethrough, and which as condensate will pass through the conduit 33, which is in flow connection with the discharge conduit 62. A conduit 37 extends through the discharge end of the dryer 34 and is in flow connection with the carburetor intake 6 where the intake is controlled by the usual regulator (not shown).

A distillate tank is provided into which the conduit 33 discharges. A liquid-gas pressure seal 62 is provided between the discharge end of the conduit 33 and the distillate tank 70. A dump valve comprising the dump valve support 65, seal 64 and seal support 66 and the level arm 69 on which the adjustable weight 67 is mounted, said Weight being anchored in a predetermined position by set screw 68.

The pump on the well is activated by the engine 42 which has the usual radiator 96, exhaust manifold and carburetor. A drive shaft 44 powers the pump in the usual manner and connected thereto is the usual mechanism which in turn operates a pump (not shown) to pump the condensate from the heat exchanger 57 through the fiow line 61 back into the engine cooling system. A thermostat in the engine diverts steam into the line 55 for conveyance into the heat exchanger. Hot exhaust gases from the engine manifold pass through the flow line 2 into the outer vessel 92 and is exhausted through the flow line 5 into the stack 78. A rain seal 79 is mounted on the top of the stack 78.

The flow line 2 will be insulated to prevent heat loss, and gases therefrom pass through the bypass assembly shown in FIGURE 5, consisting of the T 80 and the conduit 81 in flow connection with the conduit 31 forming flow line 2. The line 81 connected into the T 80 has the butterfly valve 85 and operating lever 86 pivoted outer vessel 92, which is also preferably cylindrical in form and is supported in any suitable manner as by the supports 8, 8 and which is sealed by the end plates 26, 29, the plate 29 being welded to one end of the cylinder 92 and a steel ring 24 is mounted at the other end of the cylinder 92 and bolt holes 28 are provided through the end plate 26 and ring 24 to detachably mount the said end plate 26 on the cylinder. The inner cylinder 40 has an end plate 40' welded in one end and a steel ring 16 at 92 to the piston rod 84 which is connected to the piston 88 mounted in the cylinder 82. The piston 87 is provided with a rack 89 which has an operating gear 90 controlled by a knob on the outside of the tank 92. A cylinder 97 is mounted in the inner tank 40 and is in flow connection with the T 80 by means of the line 98. This cylinder is filled with an expandible fluid. Heat changes in the exhaust chamber adjacent to the flow line 2 will reflect the amount of heat absorbed in the distillation process. If the distillate becomes too hot, the fluid inside the cylinder 97 will expand and bear against the piston 84 and open the valve 85, thus permitting hot gas to be bypassed and exhausted through the stack 63 until the heat in the vessel 92 decreases and closes the valve 85. The knob 95 may be adjusted to turn the gear 90 and adjust the position of the piston 87, which will determine the point at which the valve 85 will be opened.

The starter employed for starting the generating of gas is similar to a blow-torch (not shown) mounted in the housing 75, and which uses a starting fuel such as gasoline or distillate from the tank 70 fed through the line 77. This heats the petroleum in the tank 40 and starts the gas generation. A manually operable valve 74 opens the flow line 2 to the exhaust gas of the engine to start the flow into the vessel 92. The vein valve 79 on the exhaust stack must be propped open during the starting process to prevent back pressure.

Operation of the generator Evaporation takes place with almost all liquids, and the evaporation rate increases as the temperature of the liquid approaches the boiling point. For water, the temperature can not increase beyond the boiling point at any given pressure, but may increase with pressure. For certain complex liquids, such as petroleum, the temperature first stabilizes at the boiling point of the lightest or most volatile elements, and when these have been evaporated, it may progress to the next highest fraction. Thus, although the boiling point of certain crude oils may be as low as 110 B, it is, nevertheless, possible to heat the petroleum to a temperature at which cracking takes place, in which all of the volatiles have been boiled off and only solid tars or residues remain.

The proportion of volatiles of specific natures recoverable from any crude oil is determined by the natural processes by which petroleum was formed, as well as by the specific constituents therein, as affected by the history of petroleum since original composition, i.e., by loss of pressure due to exposure to lower hydrostatic conditions, loss of gases due to reduction to atmospheric pressure, as in faulting, and so forth.

Low gravity crude oil will not contain as much gasoline or other light fractions as higher gravity crude, but may contain a larger proportion of waxes, lubricants, gas-oils, kerosenes, diesel fuel, or bunker oils and solids. The generator hereinbefore defined is designed to operate with lower quality or gravity crude oils, and care must be taken to prevent it being filled with solids, such as coke, and the like; only a fraction of the oil passed through the still must be utilized for fuel purposes and the remainder, while still liquid of almost the same characteristics, is pumped back into the pipe line.

Preliminary to activating the generator, a study must be made of the oils to be used, and this study will reveal the percentage of the oil that may be distilled off, of the quality required.

In a specific operation, many oil wells are pumped with an electric motor, if electricity is available; or with a gasoline engine, if electricity and natural gas are not available; and it is for this primary use that we will describe the operation, although it may readily be seen that there are many more applications where the economics favor the subject invention.

In FIGURE 1 it may be seen that the oil is pumped from an oil Well by the engine 42, connected through its drive shaft 44 to a conventional well pump 45. The oil is forced through the pipe 49 into a separator 50, or a vertical tank of suflicient height to provide a head of four to five p.s.i.g. for forcing the oil through pipe 53, coils 58, pipe 52 and into the distributor tube 32. A conventional stock-tank usually found at the end of pipe 51 will provide enough head against the separator or vertical tnak for this purpose.

When the engine is pumping, the thermostatic control of the water in the cooling system maintains the coolant water in the engine at 240 F., the designed temperature. At this temperature, from the steam tables currently pub- 6 lished, it will be found that steam at 240 F. is available at slightly over 12 p.s.i.g.; a connection provided between the engine and the thermostat pipe 55 conducts the steam through the pipe 55, to the space in the heat exchanger 57 surrounding the heat exchange oil pipes 58, thus warm ing the oil to approximately 240 F. In the cooling of the steam, in giving up its heat to the oil, condensation takes place, and, if the heat exchanger is higher than the connection through the said pipe 61 to the radiator, there will be gravity drainage of the condensate to the radiator.

A valve in line 52 (not shown) meters the oil from the separator 50 into the heat exchanger 57, and thence into the oil distributor line 1 and distributor tube 32 in the distillation unit, as shown in FIGURE 2. The oil is forced out through the slots 10, 10 impinging upon the inside surface of the distillation vessel 40 which is sealed by the weight of the float 12 and arm 13 against the seal 11, closing the pipe 30 in the flow line 3 until the oil rises to the level line shown. Above this line, excess oil lifts the float and opens the sealed valve 11 and releases some oil. Since oil is continuously entering the vessel through the slots, 10, 10, there will be oil leaving continuously through the pipe 30, in the same quantity, less the fluids that have been distilled off. This excess is delivered Where desired, such as into the line 51 to the storage tank 47.

Hot exhaust gases from the exhaust manifold pass through the insulated flow line 2 to the conduit 31 and thence around the outside of the distillation vessel 40, and ultimately through the flow line 5, into the stack 78.

The distillation vessel 40 has supports, or flutes, 93, welded lengthwise at intervals around the vessel 40, which serve to increase the heat exchange, and to space the still vessel 40 within the outer vessel 92. The gases exhausted from the engine are above 1100 F., and give up heat to the heat exchange flutes and the ends and sidewalls of the still vessel 40. The oil impinging upon the sides of the tube 40 from the distributor tube 32 is thus heated to a predetermined temperature, usually 576 F., differing for different grades of petroleum, and exhaust gas will leave the stack 78 at from 250 F. to 576 F.

The exhaust connection made from the engine into the flow line 2 and conduit 31 is shown in FIGURE 5 at 80 and 81 where a temperature sensitive element senses any increase over this value, and opens the bypass valve 85, thus permitting the escape of some of the 1100 F. gases, and permitting the cooling off of the still to some extent, whereupon valve 85 closes again and full heating resumes.

Heating this oil to a temperature of 500 F. or more will distill or refine out of it a percentage of lighter hydro carbon fractions, which are of a quality and amount sufiicient to provide the maximum amount of fuel needed to satisfy the maximum performance demand of the engine. Since all engines of this general type have roughly comparable performance characteristics, a fractional distillation apparatus of this nature should satisfy any engine of approximately the same horsepower rating.

Distillation against the 600 F. inner walls of the vessel 40 will produce a frying action with sputtering droplets of oil, smoke and gases. Some of this mist will precipitate to the surface of the oil in the lower part of the chamber, but some will penetrate into the drying area within the enclosure 18, where, being at the cooler end of the still, the lower fractions will condense and settle out, through the perforations shown, collecting in the oil reservoir at the bottom of the vessel. Since, at this temperature, the vapor pressure will be several p.s.i., these gases will escape through the tube 7, which is provided with a drain tube 9 for any additional condensate in the tube, into the second dryer vessel 34 which is purposely not insulated, in order that it will be cooler by F. or more, and certain additional heavier fractions will be condensed or liquified. The remaining gas will be further de-misted through the baffle 38, perforated, and the mist screen 39. The gases entering the tube 37 and leaving the still through flow line 6 are conducted through a throttle valve (not shown) and into the engine carburetor connection.

For some engines with simple carburetors, no pressure is required, but for the larger, more complicated engines, the carburetors require positive gas fuel pressures of up to 3 oz./in. Provisions for providing these pressures are shown in FIGURE 4. To prevent any substan tial additional pressure, the device shown in FIGURE 4, attached to the distillate conduit 33, may be operated with a syphon breaker port closed, or plugged, upon which an increase in pressure will open the dump valve 64, letting out any condensate in the dryer vessel, and permitting the gases to escape through this valve until the pressure becomes normal. This situation would result from the stoppage of flow of fresh oil into the chamber 40 through the distributor tube 32, and connections, and the consequent increase of temperature in the still. This situation would also cause the bypass valve shown in FIGURE 5 to bypass hot gases, to cool down the apparatus. This would ultimately result in the starving of the engine for fuel, thus calling attention to the defect, which would be corrected before the system could be restarted. Thus, the system is seen to be self-protecting and self-controlling.

In the event distillate starts to fill the flow line 7 and the drying chamber 34, it will be seen that when it rises to the level of flow line 7, the inlet to the drying vessel, it will overflow back into conduit 7, drain down to the oil reservoir through conduit 9 and open the float valve 11, thus relieving the gas and oil pressure.

Stopping the engine obviously stops everything, and all temperatures and pressures will approach ambient within a short time.

Having thus described one form of the fractional distillation apparatus, it is seen that many modifications may be made without departing from the scope of the present invention, and that an improved, simple, automatic fuel distillation apparatus has been described, capable of being started from a cold condition with its own products, except for the first time, and complete control and protective devices are incorporated therein, and it is of the greatest simplicity commensurate with its complex requirements, and, since its fuel is the fractions of the oil produced, refined by the waste heat normally lost from an engine, the cost of such fuel is much less than that of any normally available purchasable fuel.

While the foregoing is considered a preferred form of the invention, it is by way of illustration only, the broad principle of the invention being defined by the appended claims.

What we claim is:

1. The method of converting light fractions of crude petroleum to fuel suitable for use in internal combustion engines comprising the steps of:

(a) preheating the crude in a heat exchanger in Which steam for the engine cooling system is circulated;

(b) passing said crude through a second heat exchanger where the exhaust gases of the engine are employed to provide the desired temperatures;

(c) drawing off the evaporated fractions of the crude passing through said second heat exchanger;

(d) subjecting said fractions to a drying process, and

(e) controlling the flow of the dry gases to the carburetor of said engine.

2. The method of converting light fractions of crude petroleum to fuel suitable for use in internal combustion engines as defined in claim 1, comprising the steps of:

(a) causing the crude pertoleum to flow through a heat exchanger utilizing steam from a pressurized internal combustion engine cooling system to elevate its temperature to that of the condensing steam;

(b) passing the hot crude petroleum through a second heat exchanger where the exhaust gases of the same internal combustion engine further elevate the oil temperature to the temperature necessary for distilling olf the higher fractions to the desired proportion of the total oil being treated;

(c) maintaining pressure on the crude petroleum and the gases distilled off, and retaining the gases for a sufficient time, in a sufficiently large vessel, to insure that all the oil so treated reaches the maximum temperature desired and that all larger droplets produced by the distillation are permitted to precipitate to the surface of the residue oil;

(d) passing the gases through a first mist extractor;

(e) conducting the gases to a second condenser-dryer vessel, maintained at somewhat lower temperature to cause condensation of the lowest of the light hydrocarbon fractions and the complete demisting of the remaining gas;

(f) conducting the dry gas to the carburetor of the internal combustion engine;

(g) storing the distillate from the condenser for use in starting the system.

3. The method defined in claim 1 with the addition of the step of first starting the system by the use of a pressure burner, utilizing a portion of the distillate recovered and stored from the condensation chamber.

4. The method of claim 1 in which the distillate is used as fuel for engines of the diesel type, and the gases are further condensed to liquid and returned to a stock tank.

5. Apparatus for the accomplishment of the method defined in claim 1 for converting a portion of the lighter hydrocarbons of crude petroleum to fuel suitable for use in internal combustion engines, comprising means for:

(a) distilling off a portion of the lighter fractions by first passing the crude petroleum through a heat exchanger of conventional type, having a system of pipes for conducting the petroleum, surrounded by a sealed casing having inlet and outlet connections for admitting steam from the engine cooling system, and for the escape of the water condensed from said steam;

(b) means for reinjecting the said condensate water back into the engine cooling system;

(c) means for conducting the hot oil from the first heat exchanger to a second heat exchanger-still comprising an outer sealed vessel, and an inner sealed vessel, spaced by horizontal heat conducting fins, the oil being conducted into the inner vessel and caused to be sprayed against the upper internal surface of the inner vessel by a slotted distributor tube;

(d) means for conducting the hot exhaust gases from the engine exhaust manifold to the second heat exchanger, conducting the sald hot exhaust gases against and around the ends thereof and the heat exchanger fins, and outer surfaces of the inner sealed vessel, and thence out of the outer tube to atmosphere, for the purpose of further elevating the oil temperature to the degree necessary for distilling off the fractions desired;

(e) means for collecting and demisting the gases in a first demister-dryer within the inner vessel;

(f) means for conducting the gases to a third vessel for drying and partially condensing the gases of lower fraction, which third vessel is not heated and consequently operates at a lower temperature than the inner vessel;

(g) means for maintaining a positive pressure on the produced gases, comprising liquid columns maintained in the proper pressure or head by adjustable pressure relief valves;

(h) means for controlling the level and retaining the hot fluid within internal vessel until all the fluid is heated sufficiently to distill off the desired light fractions as gas, and for releasing the amount of oil introduced into the vessel, less the fractions distilled 011, to be reinjected into the pipes to the storage tank, maintaining a liquid and vapor seal to retain all the gases so produced;

(i) means for maintaining a pressure seal and liquid seal on the condenser-dryer vessel, and for permitting the release of increments of condensate therefrom as they accumulate, to a Vessel for collection, and thence to storage, and

(j) means for conducting the dry gases to the engine carburetor for fuel to operate the engine.

6. The device defined in claim 5 having the additional steps of:

(k) means for preheating the still for production of gases for starting the engine comprising, in the first instance, a pressurized burner utilizing purchased fuel causing hot gases from the burner to enter the outer vessel of the still thus heating the inner vessel and distilling off gases sufficient to start the engine.

7. The device defined in claim 6 having the additional steps of:

(1) means for sensing the temperatures and pressures within the units of the distillation apparatus, the temperature means sensing abnormally high temperature caused by stoppage of flow of fresh crude to the system, and operating to bypass the exhaust heat until the flow is resumed; and the pressure means operating to prevent drowning of the engine by dumping excessive amounts of oil in the inner distillation vessel to the exterior, and by releasing all the condensate from the second condenser dryer vessel, thus releasing the pressure of the gas and stopping the engine.

8. Apparatus for carrying out the method defined in claim 1 for generating fuel for an internal combustion engine comprising means for diverting a portion of the oil present in a storage tank, passing said oil through a heat exchanger, maintaining the desired temperature in said heat exchanger by diverting steam from the cooling system of the engine to be supplied With fuel into said heat exchanger, passing said oil through a second heat exchanger heated by the exhaust gases of said engine, and means for drawing off the lighter fractions evaporated by said second heat exchanger, and demisting means for further drying said fractions and capturing the distillates therefrom.

References Cited UNITED STATES PATENTS 1,382,995 6/1921 Lucke 123-3 2,284,809 6/1942 Dyer et a1. 123-3 1,731,583 10/1929 Mallory 123-133 2,384,472 9/1945 Landers 123-133 2,698,055 12/1954 Williams 123-133 WENDELL E. BURNS, Primary Examiner.

U.S. Cl. X.R. 123-133 

